Study type: Medical/biological study (experimental study)

Electromagnetic fields (1.8 GHz) increase the permeability to sucrose of the blood-brain barrier in vitro med./bio.

By: Schirmacher A, Winters S, Fischer S, Goeke J, Galla HJ, Kullnick U, Ringelstein EB, Stogbauer F
Published in: Bioelectromagnetics 2000; 21 (5): 338-345
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Aim of study (acc. to author)

To evaluate the effect of high frequency electromagnetic fields on the permeability of the blood-brain barrier in a cell culture model.

Endpoint

Exposure

Exposure Parameters
Exposure 1: 1.8 GHz
Modulation type: pulsed
Exposure duration: continuous for 4 days

Exposure 1

Main characteristics
Frequency 1.8 GHz
Type
Charakteristic
  • guided field
Exposure duration continuous for 4 days
Modulation
Modulation type pulsed
Pulse width 0.577 ms
Repetition frequency 217 Hz
Exposure setup
Exposure source
  • waveguide
  • rectangular (RG22) (0.109 x 0.054 x 0.564 mm)
Chamber incubator
Setup Eight samples were exposed at a time by placing them inside the waveguide which was located in the incubator. Holes (4 mm in diameter) were drilled into the waveguide near the sample location to allow air flow and constant CO2 concentration for the culture medium.
Additional info For sham exposure, samples were placed in a second waveguide in another incubator, but no microwave power was applied.
Parameters
Measurand Value Type Method Mass Remarks
SAR 0.3 W/kg mean measured and calculated - -
SAR 0.46 W/kg maximum measured and calculated - -
Measurement and calculation details

The specific absorption rates (SAR) for the samples were obtained from a numerical calculation of the field distribution based on the Finite Difference Time Domain method (FDTD). Calculations were verified by comparing the resulting values of reflection and transmission factors with measured values and were used to establish the relation between the field distribution inside the waveguide and the microwave power transmitted through it. Thus, the SAR-values could be monitored simply by measuring the transmitted microwave power.

Exposed system:

Methods Endpoint/measurement parameters/methodology

Investigated system:
Time of investigation:
  • after exposure

Main outcome of study (acc. to author)

A definite and reproducible effect of microwave exposure on the physiological properties of the blood-brain barrier in vitro is reported. The results show a significant increase in permeability under EMF-exposure.
In conclusion, the authors report a definite and reproducible effect of microwave exposure on the physiological properties of the blood-brain barrier in vitro. Since they have checked the validity of the model of the blood-brain barrier and the exposure conditions resemble those used in mobile telecommunication, the authors emphasize the relevance of their findings to clinical medicine, as well as to basic research.

Study character:

Study funded by

Replication studies

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